Light-controlled means for opening and closing an electric circuit



July 10, 1923. 1,461.523

F. J. FRANSSON LIGHT CONTROLLED MEANS FOR OPENING AND CLOSING AN ELECTRIC CIRCUIT Filed Sept. 15 1922 l N VEN TOR.

A TTORNE Y.

Patented July 10, 1923.

uITEn STATS FIR/ANS JOEL FRANSSON, OF STOCKHOLM, SVTEDEN, ASSTG'NUE TG AIVIERICAN GAS- ACGUIVIULATOR COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

LIGHT-CONTROLLED MEANS FOR OPENING AND CLUSING AN ELECTRIC UIRCUIT.

Application filed September 15, 1922.

To all whom it may concern:

Be it known that T, FRANS J. FRANssoN, a subject of the King of Sweden, and a resident of Stockholm, Sweden, have invented an Improvement in Light-Controlled Means for Opening and Closing an Electric Circuit, of which the following is a specification.

My invention relates to an apparatus which is adapted to open and close an electric Circuit when subjected to unequal light conditions, as, for instance, light and darkness, for putting an apparatus, such as a light, which may be included within the circuit in and out of operation.

A general object of the invention is to provide new and novel means whereby an electric circuit may be controlledautomatically by the action of light upon devices which are adapted to expand unequally under the influence of light.

A further object of the invention is to provide means for yieldingly imposing a load upon the said devices, the imposition of such load having been found to effect more satisfactory operation of the apparatus.

An apparatus embodying my-invention is Well adapted for use in connection with electric signal lighting devices because it is usually the case that such devices should be operated to give forth their signals at night time only. By the employment of the apparatus embodying my invention the circuit including the light of the electric signal device is automatically opened under the influence of light so that the signal light is extinguished during periods of daylight.

It will be understood, however, that the invention is not limited to the specific or particular kind of work accomplished as a result of effecting alternate interruption and completion of the circuit in the manner as hereinabove or as may hereinafter be set forth. r

Other objects and advantages of the invention will be pointed out in the detailed description thereof which follows or will be ap arent from such description.

.11 order that the invention may be readily understood and its practical advantages fully appreciated, reference may be had to the accompanying drawing forming a part Serial No. 588,307.

of this specification and in which several forms of construction embodying the invention are illustrated.

In the said drawing:

Fig. l is a view in side elevation of a portion of one forra of apparatus embodying the invention;

Fig. 2 is a top plan view thereof;

8 is an end elevation thereof showing the electric circuit which is adapted to be controlled;

Fig. l is a schematic view elevation of a modified form 0 embodying my invention;

Fig. 5 is a top plan view of another modified form of construction thereof; and

Fig. 6 is a vertical sectional view of the construction shown in 5.

Referring to Figs. 1 to 3 inclusive of the drawing: 1 designates as a whole two sheets of suitable metal arranged and secured together as shown in the drawing. The securing of these sheets permanently together may be effected by sweating, welding or otherwise. These sheets are of different kinds of metal and have unequal coefiicients of expansion. The metal of the upper sheet 2 has a greater coefficient of expansion than has the sheet 3. The two overlyin and connected sheets 1 are cut longitudinally along the line 5--6 which may be extended inwardly from the outer free end thereof to a greater or less extent so that two tongues 4c and 4: are formed. These tongues may be entirely disconnected from each other if desired. The connected sheets 1 are secured to a block 7 of insulating material. At the outer free end or the tongue at a block 8 of insulating material is provided to which an arm 21 is secured by means of a fastening or binding screw 14, which arm extends from said block transversely over the tongue l. The adjustable contact screw 9 is secured to the arm 21 and is adapted to contact with the contact point 10 secured-to the outer end of the tongue 4. 11 designates an electric source from which extends a conduit or conductor 12 to a contact 13 secured to the tongue 4, and the fastening or binding screw 14 is connected through a conduit 15 with the opposite side of the electricity source 11. A current conartly in end construction suming applaratus, such as a light 16, is included wit in the circuit, as shown in Fig. 3 of the drawing. Instead of a light the circuit may include other means to be controlled or operated, as, for instance, a relay or an electro-magnet for regulating and controlling a valve which in turn may regulate and control the supply of gas to a gas b-irner.

In order that the tongues 4 and 4' may be unequally affected by the action of light thereon one of them, the former, should be light absorbing while the other should be light reflectin or non-light absorbing. if the tongue 4 e left unpolished while the tongue 4 is polished the former will be more light absorbing than the latter, in consequence of which it will absorb a greater amount of light and will be heated to a higher temperature than the tongue 4, in consequence of which greater expansion of the former than the latter will be effected. in order, however, to cause the tongue 4 to absorb an even greater amount of light, which, when absorbed, is converted into heat, it may be covered with a coating of black material, such as lamp black.

In the construction, as illustrated, the contact 9 is adjusted so as to abut against the contact 10 when the apparatus is surrounded by darkness; that is, when it is not subjected to light. When in such condition the current passes from the source 11 through the apparatus 16, the fastenin or binding screw .14, arm 21, contact 9 an tongue 4 to the conduit 12 and therethrough to the opposite side of the source 11. If the apparatus be a lamp it will be lighted. If, however, the a paratus be subjected to the action of light t e tongue 4, which is light absorbing, will absorb a greater quantity of light than the tongue 4. As a result, the amount of exansion in the tongue 4 will be greater than t at in the tongue 4', in consequence of which the contact 10 will separate from the con tact 9 so that the circuit will become opened or broken with the result that the apparatus 16, which is shown as a light, receives no current and is extinguished. /Vhen the darkness again comes on the members 4 and 4' return to the same temperature and the contacts 9 and 10 are brought together to again complete the circuit and cause a flow 0 current therethrough to operate the apparatus 16 whether it be a light or some other device.

For preventin or extinguishing the sparkin which is liable to take place between t e contacts 9 and 10 upon opening and closing the circuit, a condenser 17 is inserted across the circuit, as shown in Fig. 3.

Although not essential to the operation of the device it is preferred that yielding means, such as springs, be provided for imposing a load upon the tongues 4 and 4.

prises coiled springs 18 and 19 which springs are connected respectively at their upper ends to the tongues 4 and 4 near the outer ends of the latter. The lower ends of the springs are connecte-dto the opposite ends of a bar 22 to the middle or center of which the upper end of a coiled contractile spring 20 is secured. The lower end of the spring 20 is connected to the base of the apparatus, as indicated. All of these springs are under slight tension as a result of which theouter end portions of the tongues 4 and 4 are held in slightly flexed, downwardly extended position. The tension of these tongues in this manner prevents slack or lost motion of any kind during operation.

The load established by these springs per unit of surface upon both tongues should be equal in order to secure the best results.

By reason of the employment of such tensioning or load imposing means a greater or more extended movement of the tongues and of the contacts carried thereby with respect to each other is effected when one of the tongues is bent more than the other under the influence of light thereon.

in Fig. 4 is shown schematically a modified construction which is similar to that shown in Figs. 1 to 3 with the exception that the contact arrangement which is associated with the tongues 4 and 4 is double; also in the construction, as shown in this figureof the drawing, the current which fiows through the main or local circuit need not be employed for operating the current consuming apparatus, but means, adapted to be actuated by a flow of current through the said mainor local circuit, may be employed for opening and closing a relay or secondary circuit inwhich the current consuming apparatus is located. When the said means is in position to efiect closing of the relay or secondary circuit to operate the said apparatus the main or local circuit is open.

In said Fig. 4 the parts'4, 4, 7, 8, 14, 21, 11, 12, and 13 correspond to the parts correspondingly numbered in the preceding figures of the drawing.

On the underside of the tongue 4' an insulating block 8 is provided which has an arm 21 which extends transversely of and underneath the tongue 4. The said arm 21' is parallel with the arm 21 and is provided with an adjustable contact 9'. The tongue 4 is provided with a contact 10' upon its underside with which the contact 9 is adapted to contact when the apparatus is subjected to the influence'of light. A contact bridge 54, pivoted at its center as indicated, is adapted to be held in either of two tilted positions by menace a bent plate spring 62 secured to the upper side thereof, the top of which sprin is in contact with a fixed abutting rnem er 63. The tiltable or oscillatable member 5a is adapted to be actuated by the electro-magnets 51 and 57.

59 is an adjustable contact which is adapted to engage a contact 60 upon one end portion of the tiltable or oscillatable member 5 1. 61 is a secondary current source and 16 the current consuming apparatus, such as a light, inserted in the relay or secondary circult.

When the apparatus, as shown in Fig. 4, is not exposed to light; that is, is in darkness, the contact 10 abuts or contacts with the contact member 9. The circuit in which the elective-magnet 51 is included is broken at the contact 52, as shown, so that current cannot flow through-either of the electromagnets 51 or 57. At such time, however, the circuit including the source 61 is closed so that current may flow from said source through the current consuming apparatus 16 and contacts 59 and 60, the arm 54 and the conduit or conductor back to the source 61. If, liowever, the apparatus is exposed to light the bending of the tongue 4: will be greater than that of the tongue 1 so that the contact between the contacts 9 and 10 will be broken and contact between contacts 9' and 10' established. In such event current will flow through the local circuit as follows: From source 11 through the conduit 12, the contact 13 through the contacts 10' and 9 to the conduit'titl, the electro-magnet 57 to the contact 58, the arm 54 and the conduit 53 to the source 11. The electro-magnet 57 being thereby energized attracts the adjacent end of the contact arm or bridge 54 whereby contact between the contacts 59 and is broken and the secondary or relay circuit comprising the current source 61 is broken. Simultaneously the contact or engagement between the arm 54 and the contact member 58 is broken whereby the local circuit is broken.

If, when the circuit is in this condition, darkness comes on the tongues r and t return to their original position, as shown in Fig. 4, so that the contact members 9 and 10 are in contact with each other. The current in the local circuit then asses from the source 11 through the con uit 12, the contact 13, the tongue 4, contacts 10 and 9 through the conduit 15 to the electro-magnet 51 to the contact 52, the contact arm or bridge 54 and thence through the conduit 53 to the opposite side of the source 11. The electro-magnet 51 is thereby energized and I attracts the adjacent end of the contact arm 54 whereby the localcircuit is broken by disengagement of the contact arm 54 with the contact-52 so that current fiow through said circuit is interrupted and the opposite end of the contact arm 54 is moved into contact with the contact member 59 so that the secondary or relay circuit including the current source 61 is closed and the apparatus at 16, whether it be a light or any other device, laced in operation.

ln igs. 5 and 6, 26 and 27 respectively indicate two tongues independently operative with respect to each other. Each of these tongues comprises two strips of thin metal of different kinds permanently secured together as by welding or sweating. One of the tongues is light absorbing and the other 1S non-light absorbing or light reflecting. in order to render the apparatus more eflicient it is desirable that the light absorbing tongue shall be blackened as by a coating of lamp black, although if the said tongue is left unpolished it will absorb more light than the other tongue will if polished. The metal strips constituting the tongues should have different coefficients of expansion and the coeiiicient of expansion or the outer strip should be greater than that of the inner strip. One end of each of the tongues is stationarily secured to a stud or post 23 and the said tongues are bent or bowed, as shown. The free ends of the tongues are connected to the outer ends of links 28 and 29, the link 23 being connected to the outer free end of the tongue 27 and the link 29 to the outer free end of the tongue 26. Theinner end of link 28 is connected to a contact arm 31 while the inner end of the link 29 is connected to an end of a contact arm 30.

These contact arms are pivoted intermediate their ends independently of and in spaced relation to each other upon a post or shaft 36. Contact members 32 and 33 are secured upon blocks 35 and 34: of insulating material upon the outer free swinging ends of the contact arms 31 and 30. Springs 37 and 38 are provided for holding the contact arms or levers 30 and 31 in position with the contacts 32 and 33 in contact with each other when the apparatus is in darkness. Une end of each of these coiled springs is secured to a post 38'. The opposite end of the spring 37 is connected to the contactarm or lever 30 while the opposite end of the spring 30 is connected to thecontact arm or lever 31. The said springs, when the apparatus is in darkness, hold the arms or levers 30 and 31 in position with the contact members 32 and 33 in contact with each other. When the said contact members are in contact with each other the circuit from the source 39 is completed through the contacts 32 and 33, the circuit 39 and 40 and the current consuming apparatus 16. If, however, the apparatus is exposed to light the tongue 26, which is the light absorbing tongue, will be bent more than thetongue 27 whereby the contacts 32 and 33 will be moved out of contact with each other into lltl Nil

, as room or atmospheric temperature.

Having thus described my invention what 1 claim and desire to secure by Letters Patent is:

1. An electric circuit controlling means comprising a plurality of thermostatic strips supported in spaced relation with respect to each other, the temperature of one or" which, under the influence of light, is adapted to be greater than that of the other whereby diiierential movements of said strips are effected and contacts carried by said strips which are adapted to be moved out of and into contact with each other when the said strips are subjected alternately to the action of light and darkness.

2. An electric circuit controlling means comprising a plurality of flat yielding strips, each consisting of two strips of metal having different coefficients of dineanexpansion, the said yielding strips each being stationarily supported at one end thereof, the opposite end portion thereof being free to flex and one or" the said yielding strips being adapted to absorb a greater amount of heat than the other when both of said yielding strips are subjected to light whereby the free end portion thereoi is adapted toiiex through a greater are than said otheryiclding strip and contact members carried by said yielding strips which are adapted to be controlled by the differential movements of said yielding strips under the influence of light and darkness.

3. An electric circuit controlling means comprising two yielding flat strips supported in spaced relation to each other, said strips being situated in substantially the same plane, contacts carried by said strips and means whereby the alternate action of light and darkness on said strips causes movement thereof to control said contacts.

4. in means for controlling an electric circuit, the combination of two compound yielding resilient strips each comprising two thin strips of metal arranged one upon the other and permanently secured together, means for stationarily supporting one end of each of the compound strips leaving the opposite ends free to be moved and the co eificient of expansion of one of the said thin strips of each compound strip being greater than that of the other whereby under the influence of light said compound strips flex or bend through different distances.

5. In means for controlling an electric circuit, the combination of two compound yielding resilient strips each comprising two thin strips of metal arranged one upon the other and permanently secured together, means for stationarily supporting one end of each of the compound strips leaving the opposite ends free to be moved, means whereby under the influence of light said compound strips are adapted to flex or bend through different distances and means whereby such differential fiexing controls the said circuit.

6. lln. combination, two compound fiat yielding and resilient metal strips each comprising two flat strips of different metal having different coeiiicients of expansion, said strips being arranged one upon the other and permanently secured together throughout their lengths and means for supporting said compound strips in operative relation with respect to each other and the surface of one of said strips being light absorbing and that of the other light reflecting.

7. In means of the character described, the combination of two yielding and resilient metal strips, means for supporting each of said strips at a distance from one end portion thereof leaving said end portion free to be moved through an arc, yielding means for applying forces to said end portions to impose loads thereon and means for effecting differential movements of said end 7OIl1lOI1S.

8. deans of the character described comprising two compound metal strips, the temperature of one of which, when both are under the influence of light, is adapted to be greater than that of the other and yielding means for imposing loads upon the said strips.

9. An electric circuit controlling means comprising two compound metal strips, each compound strip consisting of two thin metal strips one laid upon the other and the two being permanently secured together and each of the said compound strips being stationarily supported adjacent one end leaving the opposite end portion thereof free to move, and the surface of one of said compound strips being darkened or blackened and that of the other polished, whereby upon the subjection or the said strips to the action of light the one acquires a higher temperature than the other so that differential movements of the said compound strips are effected and yielding means having con nection with the movable end portions of the said compound strips for imposing loads thereon.

10. An electric circuit controlling means comprising a plurality of compound metal strips, each strip being stationaril supported at a point adjacent one end thereof,

menses leaving the opposite end portion thereof free to be moved, contacts carried by said strips, means whereby when both strips are subjected to the action of light difierential movement relation between the said contacts is altered,

a bar, connections between the opposite ends of said bar and the said metal strips, and a tensioning spring having connection at one end to the middle of said bar and at its opposite end to a stationary anchorage, the said spring being normally under tension to im se loads upon the said strips.

11. n a device of the character described, the combination of twomembers which fie -upon being expanded, means for supporting said. members in operative relation to each other, and means whereby said members are adapted to be unequally expanded under the influence of light, an electric circuit and contact members within said circuit, saidcontact members being thereof is eifected whereby the controlled by the flexing of said members.

12. In a device of the character described, the combination of two resilient metallic members each of which consists of two thin strips of metal having different coefficients of expansion whereby the said of is greater than that of the said other member so that greater flexing movement thereof is effected, a circuit and contacts within said circuit which contacts are carried and controlled by the said resilient members.

In testimony that I claim the foregoing as my invention l have hereunto signed my name this 21st day' of July, 1922.

FRANS JQEL FRANSSON. 

